The present invention relates to an improvement of a toner replenishing apparatus in an image forming apparatus in which an image is formed by an electrophotographic method.
Ordinarily, a toner replenishing apparatus to replenish toner is equipped in an image forming apparatus by an electrophotographic method, that is, an electrophotographic apparatus, so that an amount of toner consumed by image formation is replenished, thereby an image having an appropriate density is always formed. As such the toner replenishing apparatus, various type ones exist. As one of these apparatus, there is such type of apparatus that the toner stored in a toner storing section is scraped out and supplied to a developing unit. This type of apparatus is better than a type of apparatus, for example, in which toner is dropped from a toner replenishing port by the action of gravity and supplied to the developing unit, in the point that a supplying amount of toner is relatively easily and accurately controlled by controlling the operation of a toner scraping means for scraping out the toner.
The toner replenishing apparatus disclosed in Japanese Patent Publication Open to Public Inspection No. 48930/1998 is this type of replenishing apparatus, that is, the apparatus in which toner is scraped out of the toner storing section, conveyed, and replenished.
As described above, the type of toner replenishing apparatus in which toner is scraped out by the scraping means and conveyed, has an advantage that a replenishing amount or a replenishing rate can be relatively accurately controlled, and the advantage becomes specifically conspicuous when the remaining toner amount in the toner storing section becomes small.
Normally, a remaining toner amount detecting device is equipped in the toner replenishing apparatus, and when the remaining toner amount becomes small, it outputs an alarm signal to request the toner replenishment. However, it is inconvenient that the image forming apparatus is stopped at once when the alarm signal is outputted, but it is more convenient that the image can still be formed even when the alarm signal is outputted, because the operator can have sufficient time necessary for installing a new toner container into the toner replenishing apparatus.
However, the conventional toner replenishing apparatus having the scraping means as described above, is not yet satisfactory for making the image forming apparatus continue image forming operations for some time when the remaining amount of toner becomes small. That is, when the remaining amount of toner becomes small, a toner replenishing signal is outputted from a remaining toner amount detecting device. When the toner replenishing signal has been outputted, the toner replenishing amount is too quickly decreased, so that the image forming apparatus can not have sufficient time for installing a new container, thereby, the image quality is extremely deteriorated, and the image forming apparatus is stopped by detecting the image deterioration, etc., resulting in unstable operations of the image forming apparatus, which is a problem.